CONSTITUTIVE MODELING OF CONCRETE USING A NEW FAILURE CRITERION

A nonlinear hypoelastic constitutive relation has been proposed for th e analysis of plane and axisymmetric reinforced concrete structures. E quivalent uniaxial strain concept introduced by Darwin and Pecknold, a nd the stress-strain curve for concrete proposed by Alexander have bee n used. A new ultimate strength surface for concrete is proposed. The back propagation algorithm of Rumelhart et al. [1] [D. E. Rumelhart, G . E. Hinton and R. J. Williams, Learning representations by back-propa gation errors. Nature 323, 533-536 (1986)] is used to train the artifi cial neural network for experimental results of concrete and is used t o describe the ultimate surface. Thus, a new failure criterion for con crete is proposed. The proposed constitutive model is implemented in t he user friendly finite element package ''FENLACS'' -(Finite Element N onLinear Analysis of Concrete Structures). The capability of the model to analyze a wide variety of structural engineering problems has been observed. The user friendly features of FENLACS to study the nonlinea r load deflection behavior, crack pattern and principal stress contour s have also been illustrated.